msddsc.dll and Windows 2003 .net

Hi I’m having some troubles accessing a User Portal 2.60.D from a machine with Internet Explorer 6 (SP1) and Windows 2003 Server (english evaluation version). The web parts show up correctly, but with no links. There is no left frame, with the Search form and the Layout and Settings links missing. I tried to register the msddsc.dll file, but with no success. The portal works great from machines with Windows 98, 2000 and XP, all of them with IE6 (no SP1) installed. Any ideas?